Stranded steel wire structures

ABSTRACT

A high strength ductile hot rolled rod and/or cold drawn wire made from commonly used steels including 0.65 to 1.00 percent carbon, 0.25 to 1.20 percent manganese, 0.35 percent maximum silicon, 0.20 percent maximum aluminum, 0.05 percent maximum sulphur, 0.012 percent maximum nitrogen, and 0.05 percent maximum phosphorus, but with the addition of 0.03 to 0.15 percent vanadium and 0.20 percent maximum molybdenum. Because of the vanadium and molybdenum additions the rod, after being hot rolled, requires only one patenting step in cold drawing to size and the rod and wire have improved physical characteristics.

I 75] Inventor:

[22] Filed:

United States Patent [191 Lucht STRANDED STEEL WIRE STRUCTURES Wilbert Lueht, Orange, Conn.

[73] Assignee: United States Steel Corporation,

I Pittsburgh, Pa.

Oct. 23, 1970 [21] Appl. N0.: 83,614

Related US. Application Data [63] Continuation of Ser. No. 714,084, March 18, 1968,

3,404,969 10/1968 Holmes ..l48/36X 1 Feb. 27, 1973 Primary Examiner-L. Dewayne Rutledge Assistant ExaminerJ. E. Legru Attorney-Martin J. Carroll 571 ABSTRACT A high strength ductile hot rolled rod and/or cold drawn wire made from commonly used steels including 0.65 to 1.00 percent carbon, 0.25 to 1.20 percent manganese, 0.35 percent maximum silicon,'0.20 percent maximum aluminum, 0.05 percent maximum sulphur, 0.012 percent maximum nitrogen, and 0.05 percent maximum phosphorus, but with the addition of 0.03 to 0.15 percent vanadium and 0.20 percent maximum molybdenum. Because of the vanadium and molybdenum additions the rod, after being hot rolled, requires only one patenting step in cold drawing to size and the rod and wire have improved physical characteristics.

1 Claim, No Drawings STRANDED STEEL WIRE STRUCTURES This application is a continuation of my copending application Ser. No. 714,084, filed Mar. 18, 1968, now

abandoned.

This invention relates to stranded steel wire structures and to a method of making the wires. In making cold drawn wire, especially wires to be used in stranded wire products such as wire rope, it has been necessary to M11. patent the rod before cold drawing and then patent it at least once more before reducing to final wire size. The additional patenting step increases the cost of production and it is desired to eliminate one of the patenting steps. It has also been determined that the physical characteristics of rods and wires produced from the same heat of steel will vary considerably even at different locations throughout an individual rod or wire.

I have found that by adding vanadium, either alone or with molybdenum, to steels normally used for the above purposes a more uniform product can be ob- 1 tained even when one or more patenting steps are eliminated. The invention .is-particularly adapted for producing large size wires, approximately 0.100 inch diameter and larger, whichare subjected to heavy reductions of approximately 60 percent or greater in production. g

It is therefore an object of my invention to provide a standard wire structure made from a plurality of heavily cold drawn wires of a specific steel analysis with the wires having improved ductility and moreuniform physical characteristics.

This and other objects will be more apparent after referring to the following specification which describes my invention in detail. 1

According to my invention, I add from 0.03 to 0.15 percent vanadium and up to 0.20 percent molybdenum to the steels commonly used for making 'cold drawn wire with the amount of vanadiumdecreasing as the amount of molybdenum increases. The steels contemplated include 0.65 to 1.0 percent carbon, 0.25 to 1.20 percent manganese, 0.35 percent maximum silicon, 0.20 percent maximum aluminum, 0.05 percent sulphur, 0.012 percent maximum nitrogen, 0.05 percent maximum phosphorus, 0.20 percent maximum molybdenum, 0.03-0.15 percent vanadium, and the balance iron and other elements, such as copper, nitrogen, and chromium, in residual amounts.

A specific analysis includes 0.75 percent carbon, 0.74 percent manganese, 0.23 percent silicon, 0.015 percent sulphur, 0.048 percent aluminum, 0.09percent molybdenum, 0.05 percent vanadium, with the balance iron and other elements such as copper, nitrogen and chromium'in residual amounts. Rods of various sizes were hot rolled from this steel. The sizes rolled include /64 inch diameter, 11/32 inch diameter and 5/16 inch diameter. The S/ 16 inch rod was M.I-l. patented and then drawn in six drafts to 0.150 inch. The M.I-1. patenting is a conventional heat treatment in which a rod or wire is heated to approximately 1600F. and immediately quenched in molten lead at 975F. The time in the lead may vary dependent upon the speed of travel and length of immersion in the bath, but for rods and large size wires the time is generally about one minute. This cold drawn wire had a tensile strength of 254,000 psi. with a standard deviation of 4100 psi. as

compared to a standard deviation of approximately- 8000 psi. for similar wires without the vanadium or molybdenum additions. The torsion tests showed surprisingly uniform results with seventeen 360 twists in 8 inches of length.

A second specific analysis includes 0.70 percent carbon, 0.61 percent manganese, 0.22 percent silicon, 0.021 percent sulphur, 0.013 percent phosphorus, 0.11 percent vanadium, with the remainder iron and usual residuals.

Although I have found that the hot rolled rod can be cold drawn to finish size with only one patenting step, the hot rolled rods in the following examples were M.H. patented and given a relatively small reduction by cold drawing so as to obtain a uniform circular cross section. This was done in order to accurately determine the cross sectional area so that the properties of the rod and wire could be accurately determined. Process wire so formed was then M.H. patented and given a heavy reduction to final size.

TABLE 1 MECHANICAL PROPERTIES AND CHEMICAL ANALYSIS M. H. PATENTED PROCESS WIRE Average Wire Steel Size C Mn P S Si Mo Va 1 .310 .75 .74 .008 .015 .23 .09 .05 2 .195 .75 .74 .008 .015 .23 .09 .05 3 .290 .70 .61 .013 .020 .22 .11 4 .290 .77 .70 .009 .022 .20 5 .290 .79 .62 .009 .020 .25 6 .290 .79 .62 .009 .018 .27 7 .290 .79 .62 .009 .018 .27 B .290 .79 .73 .020 .034 .25

Tensile PSI Reduction Area Standard Standard Steel Average Deviation Average Deviation 1 173,200 1,544 47.8 2.50 2 173,050 1,617 56.7 1.96 3 174,000 1,300 47 1.6 4 173,600 4,000 36.7 1.5 5 176,700 3,500 36 1.2 6 175,200 4,300 36.4 4.5 7 171,500 4,400 8 176,682 2,700 43.5 49.

Table 1 shows the properties of various steel wires after the initial cold drawing and subsequent patenting.

Samples 1, 2 and 3 are of the present invention while the remaining samples are similarly processed, but omit the vanadium and molybdenum. The tests indicate no substantial difference in the tensile strength, but Samples l, 2 and 3 are much more uniform with a standard deviation substantially less than that of the other samples. The percent reduction in area indicates the better ductility properties of the steels of the present invention. While the standard deviation for reduction in areas of Samples 4 and 5 is less than that of Samples 1, 2 and 3, the percent reduction of area is so much lower that the wire is substantially poorer in quality.

TABLE II MECHANICAL PROPERTIES ROUND Table II shows the mechanical properties of some of the wires of Table 1 when drawn to the sizes indicated with no intermediate patenting. It will be noted that the standard deviation in tensile strength is much lower for Samples 1, 2 and 3 than that of conventional wires 4, 5, 6 and 8. This indicates a uniform product. Average torsion tests were made only for wires of applicants invention and for Sample 8. This shows little difference. The average reduction in area and average elongation is shown only for the wires of applicant's invention since the other steels were tested sometime previous when it was not common to perform such tests. It will be noted that the average reduction in area, while decreased as compared to the wires prior to the final reduction, is still greater than that of the wires without vanadium and molybdenum prior to the final drawing steps.

The 0.195 inch M.H. patented process wire (Sample 2) of applicants invention was drawn a still greater amount to 0.063 inch round. Because of this greater reduction, the tensile strength is higher, but the standard deviation is still much less than that of Samples 4, 5, 6 and 8. This indicates the greater uniformity of product of this invention even when the wire is drawn to high strength levels.

It will be understood that the term cold drawn wire is used above to indicate wires which have not been annealed after the final cold drawing step, this being common usage in the art. The test results obviously relate to wires in this condition since otherwise the characteristics would be much different than indicated and the wires would not be suitable for use in making stranded structures.

While several embodiments of my invention have been shown and described, it will be apparent that other adaptations and modifications may be made without departing from the scope of the following claims.

I claim:

1. A stranded wire structure comprising a plurality of heavily cold-drawn unannealed high strength wires stranded together, each of said wires being made from steel consisting essentially of 0.65 to 1.00 percent carbon, 0.25 to 1.20 percent manganese, 0.35 percent maximum silicon, 0.20 percent maximum molybdenum, 0.03 to 0.15 percent vanadium, the amount of vanadium decreasing as the amount of molybdenum increases, 0.20 maximum aluminum, 0.05 maximum sulphur, 0.012 maximum nitrogen, 0.05 maximum phosphorus, and the balance iron and other elements in residual amounts, each of said wires having a minimum reduction of area, as measured in a tensile test of 25 percent. 

